Body mass index, waist circumference, and mortality in subjects older than 80 years: a Mendelian randomization study.

BACKGROUND AND AIMS: Emerging evidence has raised an obesity paradox in observational studies of body mass index (BMI) and health among the oldest-old (aged ≥80 years), as an inverse relationship of BMI with mortality was reported. This study was to investigate the causal associations of BMI, waist circumference (WC), or both with mortality in the oldest-old people in China. METHODS: A total of 5306 community-based oldest-old (mean age 90.6 years) were enrolled in the Chinese Longitudinal Healthy Longevity Survey (CLHLS) between 1998 and 2018. Genetic risk scores were constructed from 58 single-nucleotide polymorphisms (SNPs) associated with BMI and 49 SNPs associated with WC to subsequently derive causal estimates for Mendelian randomization (MR) models. One-sample linear MR along with non-linear MR analyses were performed to explore the associations of genetically predicted BMI, WC, and their joint effect with all-cause mortality, cardiovascular disease (CVD) mortality, and non-CVD mortality. RESULTS: During 24 337 person-years of follow-up, 3766 deaths were documented. In observational analyses, higher BMI and WC were both associated with decreased mortality risk [hazard ratio (HR) 0.963, 95% confidence interval (CI) 0.955-0.971 for a 1-kg/m2 increment of BMI and HR 0.971 (95% CI 0.950-0.993) for each 5 cm increase of WC]. Linear MR models indicated that each 1 kg/m2 increase in genetically predicted BMI was monotonically associated with a 4.5% decrease in all-cause mortality risk [HR 0.955 (95% CI 0.928-0.983)]. Non-linear curves showed the lowest mortality risk at the BMI of around 28.0 kg/m2, suggesting that optimal BMI for the oldest-old may be around overweight or mild obesity. Positive monotonic causal associations were observed between WC and all-cause mortality [HR 1.108 (95% CI 1.036-1.185) per 5 cm increase], CVD mortality [HR 1.193 (95% CI 1.064-1.337)], and non-CVD mortality [HR 1.110 (95% CI 1.016-1.212)]. The joint effect analyses indicated that the lowest risk was observed among those with higher BMI and lower WC. CONCLUSIONS: Among the oldest-old, opposite causal associations of BMI and WC with mortality were observed, and a body figure with higher BMI and lower WC could substantially decrease the mortality risk. Guidelines for the weight management should be cautiously designed and implemented among the oldest-old people, considering distinct roles of BMI and WC.

Genetic associations with longevity are on average stronger in females than in males.

It is long observed that females tend to live longer than males in nearly every country. However, the underlying mechanism remains elusive. In this study, we discovered that genetic associations with longevity are on average stronger in females than in males through bio-demographic analyses of genome-wide association studies (GWAS) dataset of 2178 centenarians and 2299 middle-age controls of Chinese Longitudinal Healthy Longevity Study (CLHLS). This discovery is replicated across North and South regions of China, and is further confirmed by North-South discovery/replication analyses of different and independent datasets of Chinese healthy aging candidate genes with CLHLS participants who are not in CLHLS GWAS, including 2972 centenarians and 1992 middle-age controls. Our polygenic risk score analyses of eight exclusive groups of sex-specific genes, analyses of sex-specific and not-sex-specific individual genes, and Genome-wide Complex Trait Analysis using all SNPs all reconfirm that genetic associations with longevity are on average stronger in females than in males. Our discovery/replication analyses are based on genetic datasets of in total 5150 centenarians and compatible middle-age controls, which comprises the worldwide largest sample of centenarians. The present study's findings may partially explain the well-known male-female health-survival paradox and suggest that genetic variants may be associated with different reactions between males and females to the same vaccine, drug treatment and/or nutritional intervention. Thus, our findings provide evidence to steer away from traditional view that "one-size-fits-all" for clinical interventions, and to consider sex differences for improving healthcare efficiency. We suggest future investigations focusing on effects of interactions between sex-specific genetic variants and environment on longevity as well as biological function.

Cognitive Benefit of a Multidomain Intervention for Older Adults at Risk of Cognitive Decline: A Cluster-Randomized Controlled Trial.

OBJECTIVE: We sought to assess cognitive benefits of a community-based multidomain intervention for improving cognition among older adults at risk of cognitive decline (COMBAT). DESIGN: A two-armed cluster-randomized controlled trial. SETTING AND PARTICIPANTS: Community-dwelling older adults aged 60 years or older and were at risk of cognitive decline (n = 209). INTERVENTION: In this 9-month intervention study, 10 community hospitals in Beijing, China, were randomized (1:1) to receive either a multidomain intervention of meditation, cognitive training, exercise, and nutrition counseling or usual care. The intervention was delivered with weekly 1-hour group training sessions and weekly home homework. MEASUREMENTS: Primary outcome was change in cognition as measured by a composite Z score of seven cognitive tests. Secondary outcomes included subjective cognitive abilities, positive and negative affective experiences, physical activity, and dietary habits. Assessments were administered at baseline, end of the intervention, and 1 year after completing the intervention (1-year follow-up). RESULTS: Immediately after the intervention, the intervention group showed significant enhancement in cognitive performance (p = 0.026). The between-group difference in the Z score of change of cognition was 0.20 (95% CI: 0.053, 0.35), with a Hedges' g of 0.40 (95% CI: 0.29, 0.50). However, this cognitive benefit was not significant at 1-year follow-up. CONCLUSION: This multidomain intervention was effective to improve cognition for at-risk individuals. Long-term effects on cognitive function and individual differences in response to the intervention deserve further investigation.

Associations Between High-Sensitivity C-Reactive Protein and All-Cause Mortality Among Oldest-Old in Chinese Longevity Areas: A Community-Based Cohort Study.

BACKGROUND: The association between high-sensitivity C-reactive protein (hsCRP) levels and all-cause mortality for the oldest-old (aged 80 years or older) remains unclear. We aimed to investigate the associations between hsCRP concentrations and the risks of all-cause mortality, and further identify the potential modifying factors affecting these associations among the oldest-old. METHODS: This prospective, community-based cohort study included 2,206 participants aged 80 years or older (median age 93.0 years) from the Healthy Aging and Biomarkers Cohort Study. Cox proportional hazards regression models were used to estimate hazard ratios (HRs) with 95% confidential intervals (95% CIs) for all-cause mortality according to hsCRP quartiles and recommendation for relative risk categories of hsCRP levels (< 1.0, 1.0-3.0, and > 3.0 mg/L), with adjustment for sociodemographic information, lifestyle, physical examination, medical history, and other potential confounders. RESULTS: During a median follow-up period of 3.1 years (IQR: 1.6-3.9 years), 1,106 deaths were verified. After full adjustment for potential confounders, a higher hsCRP concentration was positively associated with an increased risk of all-cause mortality (P for trend < 0.001). Compared with the lowest quartile, the fully adjusted HRs of the second, third, and fourth quartiles were 1.17 (95% CI: 0.94, 1.46), 1.28 (95% CI: 1.01, 1.61), and 1.49 (95% CI: 1.20, 1.87), respectively. The association of hsCRP with all-cause mortality was modified by smoking status (P for interaction = 0.011), an increased risk of hsCRP with all-cause mortality showed among non-current smokers (HR: 1.17; 95% CI: 1.07, 1.28), but no significance was observed in current smokers (HR: 0.83; 95% CI: 0.66, 1.18). CONCLUSIONS: Our study indicated that elevated hsCRP concentrations were associated with a higher risk of all-cause mortality among Chinese oldest-old. Future studies investigating additional factors of disease and aging processes are needed to obtain a better understanding of the mechanisms.

Albumin-Corrected Fructosamine Predicts All-Cause and Non-CVD Mortality Among the Very Elderly Aged 80 Years or Older Without Diabetes.

BACKGROUND: Several guidelines have suggested alternative glycemic markers for hemoglobin A1c among older adults with limited life expectancy or multiple coexisting chronic illnesses. We evaluated associations between fructosamine, albumin-corrected fructosamine (AlbF), fasting plasma glucose (FPG), and mortality in the diabetic and nondiabetic subpopulations, and compared which marker better predicts mortality among participants aged 80 and older. METHODS: Included were 2 238 subjects from the Healthy Ageing and Biomarkers Cohort Study (2012-2018) and 207 participants had diabetes at baseline. Multivariable Cox proportional hazards regression models investigated the associations of fructosamine, AlbF, FPG, and all-cause, cardiovascular disease (CVD), and non-CVD mortality in the diabetic and nondiabetic subpopulations. Restricted cubic splines explored potential nonlinear relations. C-statistic, integrated discrimination improvement (IDI), and net reclassification improvement (NRI) evaluated the additive value of different glycemic markers to predict mortality. RESULTS: Overall, 1 191 deaths were documented during 6 793 person-years of follow-up. In the linear model, per unit increases of fructosamine, AlbF, and FPG were associated with a higher risk of mortality in nondiabetic participants, with hazard ratios of 1.02 (1.00, 1.05), 1.27 (1.14, 1.42), and 1.04 (0.98, 1.11) for all-cause mortality, and 1.04 (1.00, 1.07), 1.38 (1.19, 1.59), and 1.10 (1.01, 1.19) for non-CVD mortality, respectively. Comparisons indicated that AlbF better predicts all-cause and non-CVD mortality in nondiabetic participants with significant improvement in IDI and NRI. CONCLUSIONS: Higher concentrations of fructosamine, AlbF, and FPG were associated with a higher risk of all-cause or non-CVD mortality among the very elderly where AlbF may constitute an alternative prospective glycemic predictor of mortality.

The obesity paradox is mostly driven by decreased noncardiovascular disease mortality in the oldest old in China: a 20-year prospective cohort study.

National and international recommendations of healthy body mass index (BMI) are primarily based on evidence in young and middle-aged populations, with an insufficient representation of the oldest old (aged ≥80 years). Here, we report associations between BMI and mortality risk in 27,026 community-dwelling oldest old (mean age, 92.7 ± 7.5 years) in China from 1998 to 2018. Nonlinear curves showed reverse J-shaped associations of BMI with cardiovascular disease (CVD), non-CVD and all-cause mortality, with a monotonic decreased risk up to BMIs in the overweight and mild obesity range and flat hazard ratios thereafter. Compared to normal weight, overweight and obesity were significantly associated with decreased non-CVD and all-cause mortality, but not with CVD mortality. Similar associations were found for waist circumference. Our results lend support to the notion that optimal BMI in the oldest old may be around the overweight or mild obesity range and challenge the application of international and national guidelines on optimal BMI in this age group.

High Blood Uric Acid Is Associated With Reduced Risks of Mild Cognitive Impairment Among Older Adults in China: A 9-Year Prospective Cohort Study.

Background: It remains unsolved that whether blood uric acid (UA) is a neuroprotective or neurotoxic agent. This study aimed to evaluate the longitudinal association of blood UA with mild cognitive impairment (MCI) among older adults in China. Methods: A total of 3,103 older adults (aged 65+ years) free of MCI at baseline were included from the Healthy Aging and Biomarkers Cohort Study (HABCS). Blood UA level was determined by the uricase colorimetry assay and analyzed as both continuous and categorical (by quartile) variables. Global cognition was assessed using the Mini-Mental State Examination four times between 2008 and 2017, with a score below 24 being considered as MCI. Cox proportional hazards models were used to examine the associations. Results: During a 9-year follow-up, 486 (15.7%) participants developed MCI. After adjustment for all covariates, higher UA had a dose-response association with a lower risk of MCI (all P for  trend < 0.05). Participants in the highest UA quartile group had a reduced risk [hazard ratio (HR), 0.73; 95% (CI): 0.55-0.96] of MCI, compared with those in the lowest quartile group. The associations were still robust even when considering death as a competing risk. Subgroup analyses revealed that these associations were statistically significant in younger older adults (65-79 years) and those without hyperuricemia. Similar significant associations were observed when treating UA as a continuous variable. Conclusions: High blood UA level is associated with reduced risks of MCI among Chinese older adults, highlighting the potential of managing UA in daily life for maintaining late-life cognition.

Prevalence and Correlates of Healthy Aging Among Elderly Aged 65 Years and Over - 6 PLADs, China, 2019.

SUMMARY: What is already known on this topic? Healthy aging among Chinese older people has low prevalence. Some sociodemographic and lifestyle factors were shown to be associated with healthy aging. What is added by this report? The age-adjusted prevalence of healthy aging in the 6 provincial-level administrative divisions (PLADs) of China is 15.8 % in 2019. County-level factors, such as the prevalence of healthy communities in a county, as well as some sociodemographic variables and physical exercise, are potential factors of healthy aging. What are the implications for public health practice? These findings showed that more targeted actions, including generalizing healthy communities and individual-level interventions, may be of great importance for healthy aging.

Smoking cessation in late life is associated with increased risk of all-cause mortality amongst oldest old people: a community-based prospective cohort study.

OBJECTIVE: we aimed to investigate the association of smoking cessation with risk of all-cause mortality amongst oldest old people (aged ≥ 80 years). DESIGN: this was a prospective cohort study. SETTING: the Chinese Longitudinal Healthy Longevity Survey, implemented in 23 provinces of China. PARTICIPANTS: a total of 28,643 community-dwelling oldest old people (mean age, 92.9 ± 7.5 years) were included. METHODS: in this community-based cohort study, Cox proportional hazards models were used to examine the association of smoking cessation with risk of all-cause mortality. RESULTS: during 136,585 person-years of follow-up from baseline to 1 September 2014, compared with never smokers, hazard ratios and 95% confidence intervals for all-cause mortality were 1.06 (1.02-1.10) for current smokers, 1.23 (1.09-1.39) for transient quitters (≤1 consecutive years since smoking cessation), 1.22 (1.12-1.32) for recent quitters (2-6 consecutive years since smoking cessation) and 1.11 (1.02-1.22) for long-term quitters (>6 consecutive years since smoking cessation). Cox models with penalised splines revealed an increased risk of all-cause mortality after smoking cessation; the highest mortality risk was observed within 2-4 years after smoking cessation and the risk gradually decreased with duration of smoking cessation. We further conducted subgroup analyses and sensitivity analyses to reduce the impact of reverse causation. CONCLUSIONS: smoking is harmful to health in all populations. Our study findings indicated smoking cessation in late life to be associated with increased risk of all-cause mortality amongst oldest old people who have smoked for a long time.

Association Between Plasma 25-hydroxyvitamin D Concentrations and Incident Activities of Daily Living Disability: A Longitudinal Community-Based Cohort Study.

OBJECTIVES: A few studies of Western populations have found inconsistent results regarding the associations between vitamin D status and physical function. We explored the association between circulating vitamin D status [plasma 25-hydroxyvitamin D, 25(OH)D] and incident activities of daily living (ADL) disability among Chinese older adults. DESIGN: Community-based longitudinal cohort study. SETTING AND PARTICIPANTS: A total of 2453 men and women (median age 84.0 years) in 7 Chinese longevity areas were included. MEASURES: Cox proportional hazards regression models were used to estimate hazard ratios (HRs) with 95% confidence intervals (CIs) for incident ADL, with adjustments for potential sociodemographic, and lifestyle confounders and biomarkers. Because there was a statistically significant interaction between plasma 25(OH)D and sex in relation to incident ADL, men and women were analyzed separately. RESULTS: The median concentrations of plasma 25(OH)D were 46.6 nmol/L and 36.4 nmol/L for men and women, respectively. Compared with the lowest quartile in the fully adjusted model, the HR for incident ADL disability for the highest quartile was 0.55 (95% CI 0.36-0.85) for women; for men, a null association was indicated (HRhighest vs lowest 0.61, 95% CI 0.37-1.00). However, when using the recommended circulating 25(OH)D thresholds by the US Institute of Medicine, those with vitamin D sufficiency (≥50 nmol/L) had better ADL disability prognoses than those with vitamin D deficiency (<30 nmol/L) in both sexes (men HR 0.45, 95% CI 0.28-0.72; women HR 0.58, 95% CI 0.37-0.90). CONCLUSIONS AND IMPLICATIONS: The relationship between plasma 25(OH)D concentration and incident ADL disability was sex-specific among Chinese older adults. However, participants with recommended vitamin D sufficiency may have better disability prognoses in both sexes, suggesting that the recommended 25(OH)D concentration for bone health may extend to functional outcomes such as ADL disability in Chinese older adults.

Fine Particulate Matter and Poor Cognitive Function among Chinese Older Adults: Evidence from a Community-Based, 12-Year Prospective Cohort Study.

BACKGROUND: Research on the relationship between long-term exposure to particulate matter with aerodynamic diameter ≤2.5µm (PM2.5) and poor cognitive function is lacking in developing countries, especially in highly polluted areas. OBJECTIVES: We evaluated associations of long-term exposure to PM2.5 with poor cognitive function in a diverse, national sample of older adults in China. METHODS: This analysis included data on 13,324 older adults (5,879 who were 65-79 years of age, 3,052 who were 80-89 years of age, 2,634 who were 90-99 years of age, and 1,759 who were ≥100 years of age) with normal cognitive function at baseline from March 2002 to September 2014, with 64,648 person-years of follow-up. We used a geographic information system analysis to estimate the annual average satellite-derived PM2.5 concentration for the geocoded location of the participants' baseline residences. Poor cognitive function was defined as a score of less than 18 on the Chinese version of the Mini-Mental State Examination (MMSE). Competing risk models were performed to explore the association of PM2.5 with poor cognitive function. RESULTS: Each 10-µg/m3 increase in PM2.5 was associated with a 5.1% increased risk of poor cognitive function [adjusted hazard ratio (HR): 1.051; 95% confidence interval (CI): 1.023, 1.079]. Compared to the lowest quartile of PM2.5 (<41.4 µg/m3), adjusted HR values were 1.20 (95% CI: 1.09, 1.33), 1.27 (95% CI: 1.15, 1.41), and 1.21 (95% CI: 1.09, 1.34) for the second (≥41.4-50.3 ug/m3), third (≥50.3-60.7µg/m3), and fourth (≥60.7 µg/m3) quartiles of PM2.5, respectively (p for trend <0.001). Subgroup analyses suggested stronger associations between PM2.5 and poor cognitive impairment in men than women. The association was positive in the 65- to 79- and ≥100-y age group but not significant and positive in the other two age groups with similar results. CONCLUSION: PM2.5 was identified as a risk factor for poor cognitive function in Chinese older adults. Improving air quality may reduce the future population burden of poor cognitive function, especially in areas with high air pollution. https://doi.org/10.1289/EHP5304.

Development and Validation of a Nomogram for Predicting the 6-Year Risk of Cognitive Impairment Among Chinese Older Adults.

OBJECTIVE: Although some people with mild cognitive impairment may not suffer from dementia lifelong, about 5% of them will progress to dementia within 1 year in community settings. However, a general tool for predicting the risk of cognitive impairment was not adequately studied among older adults. DESIGN: Prospective cohort study. SETTING: Community-living, older adults from 22 provinces in China. PARTICIPANTS: We included 10,066 older adults aged 65 years and above (mean age, 83.2 ± 11.1 years), with normal cognition at baseline in the 2002-2008 cohort and 9354 older adults (mean age, 83.5 ± 10.8 years) in the 2008-2014 cohort of the Chinese Longitudinal Healthy Longevity Survey. METHODS: We measured cognitive function using the Chinese version of the Mini-Mental State Examination. Demographic, medical, and lifestyle information was used to develop the nomogram via a Lasso selection procedure using a Cox proportional hazards regression model. We validated the nomogram internally with 2000 bootstrap resamples and externally in a later cohort. The predictive accuracy and discriminative ability of the nomogram were measured by area-under-the-curves and calibration curves, respectively. RESULTS: Eight factors were identified with which to construct the nomogram: age, baseline of the Mini-Mental State Examination, activities of daily living and instrumental activities of daily living score, chewing ability, visual function, history of stroke, watching TV or listening to the radio, and growing flowers or raising pets. The area-under-the-curves for internal and external validation were 0.891 and 0.867, respectively, for predicting incident cognitive impairment. The calibration curves showed good consistency between nomogram-based predictions and observations. CONCLUSIONS AND IMPLICATIONS: The nomogram-based prediction yielded consistent results in 2 separate large cohorts. This feasible prognostic nomogram constructed using readily ascertained information may assist public health practitioners or physicians to provide preventive interventions of cognitive impairment.

Cluster randomised controlled trial of home cook intervention to reduce salt intake in China: a protocol study.

INTRODUCTION: Salt intake in China is twice the upper limit recommended by the WHO, and nearly 80% of salt is added during cooking. This study will develop a package of salt reduction interventions targeting home cooks and evaluate its effectiveness and feasibility for scale-up. METHODS AND ANALYSIS: A cluster randomised controlled trial design is adopted in this study, which will be conducted in six provinces covering northern, central and southern China. For each province, 10 communities/villages (clusters) with 13 families (one cook and one adult family member) will be selected in each cluster for evaluation. In total, 780 home cooks and 780 adult family members will be recruited. The home cooks in the intervention group will be provided with the intervention package, including community-based standardised offline and online health education and salt intake monitoring. The duration of the intervention will be 1 year. The primary outcome is the difference between the intervention and control group in change in salt intake as measured by 24 hours urinary sodium from baseline to the end of the trial. The secondary outcome is the difference between the two groups in the change in salt-related knowledge, attitude and practice and blood pressure (BP). ETHICS AND DISSEMINATION: The study has been approved by The Queen Mary Research Ethics Committee (QMERC2018/13) and Institutional Review Board of the Chinese Center for Disease Control and Prevention (No. 201801). The study findings will be disseminated widely through conference presentations and peer-reviewed publications and the general media. TRIAL REGISTRATION NUMBER: ChiCTR1800016804.

Number of natural teeth, denture use and mortality in Chinese elderly: a population-based prospective cohort study.

BACKGROUND: The associations between the number of natural teeth/denture use and all-cause mortality remain unclear due to lake of investigation for the potential interaction between tooth loss and denture use and for the potential changes in these exposures over time in older adults. We undertake this study to evaluate the associations of the number of natural teeth and/or denture use with mortality in Chinese elderly. METHODS: This is a prospective cohort study of 36,283 older adults (median age: 90). The number of natural teeth and denture use were collected with structured questionnaire. We evaluated hazard ratios (HRs) and confidence intervals (CIs) using a Cox proportional hazards model adjusting for demographic factors, education, income, lifestyle factors, and comorbidities. RESULTS: We documented 25,857 deaths during 145,947 person-years of observation. Compared to those with 20+ teeth, tooth loss was associated with a gradual increase in mortality, with an adjusted HR of 1.14 (95% CI, 1.06 to 1.23) for those with 10-19 teeth, 1.23 (95% CI, 1.15 to 1.31) for those with 1-9 teeth, and 1.35 (95% CI, 1.26 to 1.44) for those without natural teeth. Denture use was associated with lower risk of mortality (adjusted HR 0.81; 95% CI, 0.77 to 0.84). Subgroup analyses indicated that the benefit of denture use was greater in men than in women (P = 0.02) and tended to decrease with age (P < 0.001). The effects of denture use did not differ among various degrees of tooth loss (P = 0.17). CONCLUSIONS: Tooth loss was associated with an increased risk of mortality in older adults. Denture use provided a protective effect against death for all degrees of tooth loss however, this effect appeared to be modified by sex and age.

Plasma element levels and risk of chronic kidney disease in elderly populations (≥ 90 Years old).

Associations between plasma elements and chronic kidney disease (CKD) among the elderly are poorly understood. In this cross-sectional study, we explored the associations between exposure to four plasma elements and CKD in elderly people aged ≥90 years in longevity areas in China. We measured plasma selenium, manganese, iron, and zinc levels and used logistic regression models to investigate associations between CKD and these four plasma elements after adjusting for confounding factors among 461 participants aged ≥90 years in the fifth wave of the Chinese Longitudinal Healthy Longevity Study (CLHLS) conducted in 2009. The median plasma selenium, manganese, iron, and zinc levels were 120.51 µg/L, 26.64 µg/L, 2880.52 µg/L, and 1882.42 µg/L in the CKD group and 108.76 µg/L, 31.55 µg/L, 4512.00 µg/L, and 2294.24 µg/L in the non-CKD group, respectively. Single- and multiple-element multivariable models showed that plasma manganese, iron, and zinc were negatively associated with CKD. In the multiple-element multivariable models, the adjusted odds ratios for CKD were 0.48 (95% confidence interval [CI]: 0.27-0.86) for the second highest quartile of manganese, 0.37 (95% CI: 0.21-0.68) and 0.36 (95% CI: 0.19-0.65) for the third highest and highest quartiles of iron, respectively, and 0.53 (95% CI: 0.29-0.94) for the highest quartile of zinc, compared with the lowest quartiles of these three elements. Plasma manganese, iron, and zinc levels protect against CKD in elderly people aged ≥90 years in longevity areas.

Long-term exposure to ambient fine particulate matter and fasting blood glucose level in a Chinese elderly cohort.

Fasting blood glucose level is the primary indicator for the diagnosis of diabetes. We aim to conduct a longitudinal study on the association between long-term fine particulate matter (PM2.5) exposure and fasting blood glucose concentrations. We recruited and followed up 1449 participants older than 65 years of age in 2009, 2012, 2014, and 2017 in eight counties in China. Fasting blood glucose was repeatedly measured 3697 times in total among these participants. Data on annual ground-level PM2.5 concentrations with a 0.01° spatial resolution from 2005 to 2016 were used to assess exposures. An increase of 10 µg/m3 in 3-year average exposure to PM2.5 was associated with an increase of 0.146 mmol/L (95% confidence interval [CI]: 0.045, 0.248) in fasting blood glucose in all participants. The association was more pronounced among the subgroup with diabetes compared to the subgroup without diabetes (P < .05). In conclusion, Long-term PM2.5 exposure was associated with an increase in fasting blood glucose levels among elderly people. Elderly individuals with diabetes are particularly vulnerable to high level exposures of PM2.5. SUMMARY: Long-term PM2.5 exposure was associated with an increase in fasting blood glucose levels among elderly people. Elderly individuals with diabetes are particularly vulnerable to high level exposures of PM2.5.

Specific Leisure Activities and Cognitive Functions Among the Oldest-Old: The Chinese Longitudinal Healthy Longevity Survey.

BACKGROUND: Little is known about the role of specific leisure activities in affecting cognitive functions. We aim to examine the associations of specific leisure activities with the risk of cognitive impairment among oldest-old people in China. METHODS: This community-based prospective cohort study included 10,741 cognitively normal Chinese individuals aged 80 years or older (median age 88 years) from the Chinese Longitudinal Healthy Longevity Survey. Cognitive function was assessed using the Mini-Mental State Examination (MMSE). Cox proportional hazards models were utilized to estimate the effects of specific leisure activities on cognitive impairment outcome. RESULTS: During a median follow-up time of 3.4 years (41,760 person-years), 2,894 participants developed cognitive impairment. Compared to those who "never" engaged in watching TV or listening to radio, reading books or newspapers, and playing cards or mah-jong, those who engaged in such activities "almost every day" reduced their risk of cognitive impairment, the fully-adjusted hazard ratios were 0.56 (0.51-0.61), 0.64 (0.53-0.78), and 0.70 (0.56-0.86), respectively. The association between the risk of cognitive impairment and watching TV and listening to the radio, playing cards or mah-jong, and reading books or newspapers were stronger among those who had two or more years of education. Moreover, the association between risk of cognitive impairment and watching TV and listening to radio was stronger in men than in women. CONCLUSIONS: In conclusion, a greater frequency of TV watching or radio listening, reading books or newspapers, and playing cards or mah-jong may decrease the risk of cognitive impairment among the oldest-old.

Trends in the Incidence of Activities of Daily Living Disability Among Chinese Older Adults From 2002 to 2014.

BACKGROUND: Evidence of the trend of the incidence of activities of daily living (ADL) disability among Chinese older people is limited. We aimed to investigate the time trends and potential risk factors for the incidence of ADL disability among Chinese older people (≥65 years). METHODS: We established two consecutive and nonoverlapping cohorts (6,857 participants in the 2002 cohort and 5,589 participants in the 2008 cohort) from the Chinese Longitudinal Healthy Longevity Survey. ADL disability was defined as the need for assistance with at least one essential activity (dressing, bathing, toileting, eating, indoor activities, and continence). Cox proportional hazards models were used to identify factors associated with the trend in the incidence of ADL disability from 2002 to 2014. RESULTS: The incidence (per 1,000 person-years) of ADL disability decreased significantly from 64.2 in the 2002 cohort to 46.6 in the 2008 cohort (p < .001), and decreasing trends in the incidence of ADL disability were observed for all sex, age, and residence subgroups (all p < .001), even after adjusting for multiple potential confounding factors. Moreover, we found that adjustment for sociodemographic, lifestyle information, and cardiovascular risk factors (hypertension, diabetes, heart disease, and stroke) explained less of the decline in ADL disability during the period from 2002 to 2014. CONCLUSION: The incidence of ADL disability among the older adults in China appears to have decreased during the study period, and this finding cannot be explained by existing sociodemographic and lifestyle information and cardiovascular risk factors.

Age, Period, and Cohort Effects on Activities of Daily Living, Physical Performance, and Cognitive Functioning Impairment Among the Oldest-Old in China.

BACKGROUND: The aim of this study was to examine the trends in impairment regarding activities of daily living (ADL), physical performance, and cognitive function among the oldest-old (those aged 80 and older) in China between 1998 and 2014. METHODS: We used data on 34,297 oldest-old individuals from the seven waves of the Chinese Longitudinal Healthy Longevity Study. We estimated age, period, and cohort effects on the prevalence of self-reported ADL impairment, tested physical performance and cognitive function impairment using the age-period-cohort model. RESULTS: Regarding age, the prevalence of ADL, physical performance, and cognitive function impairment were highest in the centenarians, but they did not increase with age in this population. Among the literate subgroup, the prevalence of cognitive impairment increased more rapidly with age than that in the illiterate subgroup. Regarding period, the prevalence of self-reported and tested physical impairment slowly increased between 1998 and 2014, but cognitive impairment remained stable. Regarding cohort, ADL impairment continuously decreased. However, physical and cognitive impairment remained stable after a brief decline in the early birth cohorts. CONCLUSIONS: The results suggest that the age effect is still the most obvious effect regarding several types of functional impairment. The likelihood of a younger person experiencing functional impairment may not change significantly, but ADL is likely to be amenable to improvement resulting from improved medical and social care. Therefore, increased care for the oldest-old may considerably improve their quality of life, particularly regarding their basic ADL.

Higher dietary diversity scores and protein-rich food consumption were associated with lower risk of all-cause mortality in the oldest old.

BACKGROUND & AIMS: Dietary diversity is widely advocated in national and international recommendations although whether the beneficial effects on survival or longevity still apply in the final phase of the lifespan remains understudied. We aimed to prospectively examine the association of dietary diversity, food items with all-cause mortality among the oldest old (80+) and determine whether dietary diversity recommendations were appropriate for this population. METHODS: The study included 28,790 participants aged 80+ (9957 octogenarians, 9925 nonagenarians, and 8908 centenarians). A baseline dietary diversity score (DDS) was constructed based on nine food items of a food frequency questionnaire. Cox models with penalized splines evaluated non-linear associations of DDS as continuous variable with mortality to identify cut-offs of DDS. RESULTS: We documented 23,503 deaths during 96,739 person-years of follow-up. Each one unit increase in DDS was associated with a 9% lower risk of mortality (adjusted hazard ratio (HR): 0.91; 95% confidential interval (CI): 0.90-0.92). Compared to participants whose DDS less than 2 scores, those with a DDS of 2, 3, 4, 5, and higher than 6 scores had a lower mortality risk, the HRs were 0.86 (0.82-0.89), 0.78 (0.75-0.81), 0.69 (0.66-0.72), 0.65 (0.62-0.68), and 0.56 (0.53-0.58) respectively, and a significant trend emerged (p < 0.001). Protein-rich food items were associated with prominent beneficial effects on mortality including meat (HR and 95% CI for high vs low frequency: 0.70 (0.68-0.72)), fish and sea food (HR, 0.74 (0.72-0.77)), egg (HR, 0.75 (0.73-0.77)), and bean (HR, 0.80 (0.78-0.82)). CONCLUSIONS: Even after the age of 80, the DDS tool may offer a simple and straightforward mean of identifying and screening individuals at high risk for mortality. Recommendation of dietary diversity, especially consumption of protein-rich food, may be advocated to reduce mortality risk and promote longevity in the oldest old.